Chengyu Song
2015-Mar-24 05:28 UTC
[Ocfs2-devel] [PATCH 1/1] ocfs2: incorrect check for debugfs returns
debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.
This patch tries to solve this problem by fixing certain checks. However,
I have that found other call sites are protected by #ifdef CONFIG_DEBUG_FS.
In current implementation, if CONFIG_DEBUG_FS is defined, then the above
two functions will never return any ERROR_VALUE. So another possibility
to fix this is to surround all the buggy checks/functions with the same
#ifdef CONFIG_DEBUG_FS. But I'm not sure if this would break any
functionality,
as only OCFS2_FS_STATS declares dependency on DEBUG_FS.
Signed-off-by: Chengyu Song <csong84 at gatech.edu>
---
fs/ocfs2/cluster/heartbeat.c | 42 +++++++++++++++++++++++++++++++-----------
fs/ocfs2/dlmglue.c | 2 +-
fs/ocfs2/super.c | 9 +++++----
3 files changed, 37 insertions(+), 16 deletions(-)
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 16eff45..8e19b9d 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1312,7 +1312,9 @@ static int o2hb_debug_init(void)
int ret = -ENOMEM;
o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
- if (!o2hb_debug_dir) {
+ if (IS_ERR_OR_NULL(o2hb_debug_dir)) {
+ ret = o2hb_debug_dir ?
+ PTR_ERR(o2hb_debug_dir) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -1325,7 +1327,9 @@ static int o2hb_debug_init(void)
sizeof(o2hb_live_node_bitmap),
O2NM_MAX_NODES,
o2hb_live_node_bitmap);
- if (!o2hb_debug_livenodes) {
+ if (IS_ERR_OR_NULL(o2hb_debug_livenodes)) {
+ ret = o2hb_debug_livenodes ?
+ PTR_ERR(o2hb_debug_livenodes) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -1338,7 +1342,9 @@ static int o2hb_debug_init(void)
sizeof(o2hb_live_region_bitmap),
O2NM_MAX_REGIONS,
o2hb_live_region_bitmap);
- if (!o2hb_debug_liveregions) {
+ if (IS_ERR_OR_NULL(o2hb_debug_liveregions)) {
+ ret = o2hb_debug_liveregions ?
+ PTR_ERR(o2hb_debug_liveregions) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -1352,7 +1358,9 @@ static int o2hb_debug_init(void)
sizeof(o2hb_quorum_region_bitmap),
O2NM_MAX_REGIONS,
o2hb_quorum_region_bitmap);
- if (!o2hb_debug_quorumregions) {
+ if (IS_ERR_OR_NULL(o2hb_debug_quorumregions)) {
+ ret = o2hb_debug_quorumregions ?
+ PTR_ERR(o2hb_debug_quorumregions) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -1366,7 +1374,9 @@ static int o2hb_debug_init(void)
sizeof(o2hb_failed_region_bitmap),
O2NM_MAX_REGIONS,
o2hb_failed_region_bitmap);
- if (!o2hb_debug_failedregions) {
+ if (IS_ERR_OR_NULL(o2hb_debug_failedregions)) {
+ ret = o2hb_debug_failedregions ?
+ PTR_ERR(o2hb_debug_failedregions) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -2000,7 +2010,8 @@ static int o2hb_debug_region_init(struct o2hb_region *reg,
struct dentry *dir)
reg->hr_debug_dir
debugfs_create_dir(config_item_name(®->hr_item), dir);
- if (!reg->hr_debug_dir) {
+ if (IS_ERR_OR_NULL(reg->hr_debug_dir)) {
+ ret = reg->hr_debug_dir ? PTR_ERR(reg->hr_debug_dir) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -2013,7 +2024,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg,
struct dentry *dir)
O2HB_DB_TYPE_REGION_LIVENODES,
sizeof(reg->hr_live_node_bitmap),
O2NM_MAX_NODES, reg);
- if (!reg->hr_debug_livenodes) {
+ if (IS_ERR_OR_NULL(reg->hr_debug_livenodes)) {
+ ret = reg->hr_debug_livenodes ?
+ PTR_ERR(reg->hr_debug_livenodes) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -2025,7 +2038,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg,
struct dentry *dir)
sizeof(*(reg->hr_db_regnum)),
O2HB_DB_TYPE_REGION_NUMBER,
0, O2NM_MAX_NODES, reg);
- if (!reg->hr_debug_regnum) {
+ if (IS_ERR_OR_NULL(reg->hr_debug_regnum)) {
+ ret = reg->hr_debug_regnum ?
+ PTR_ERR(reg->hr_debug_regnum) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -2037,7 +2052,9 @@ static int o2hb_debug_region_init(struct o2hb_region *reg,
struct dentry *dir)
sizeof(*(reg->hr_db_elapsed_time)),
O2HB_DB_TYPE_REGION_ELAPSED_TIME,
0, 0, reg);
- if (!reg->hr_debug_elapsed_time) {
+ if (IS_ERR_OR_NULL(reg->hr_debug_elapsed_time)) {
+ ret = reg->hr_debug_elapsed_time ?
+ PTR_ERR(reg->hr_debug_elapsed_time) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
@@ -2049,13 +2066,16 @@ static int o2hb_debug_region_init(struct o2hb_region
*reg, struct dentry *dir)
sizeof(*(reg->hr_db_pinned)),
O2HB_DB_TYPE_REGION_PINNED,
0, 0, reg);
- if (!reg->hr_debug_pinned) {
+ if (IS_ERR_OR_NULL(reg->hr_debug_pinned)) {
+ ret = reg->hr_debug_pinned ?
+ PTR_ERR(reg->hr_debug_pinned) : -ENOMEM;
mlog_errno(ret);
goto bail;
}
- ret = 0;
+ return 0;
bail:
+ debugfs_remove_recursive(reg->hr_debug_dir);
return ret;
}
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 11849a4..23adcbf 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2954,7 +2954,7 @@ static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
osb->osb_debug_root,
osb,
&ocfs2_dlm_debug_fops);
- if (!dlm_debug->d_locking_state) {
+ if (IS_ERR_OR_NULL(dlm_debug->d_locking_state)) {
ret = -EINVAL;
mlog(ML_ERROR,
"Unable to create locking state debugfs file.\n");
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 2667518..fb43de5 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1112,7 +1112,7 @@ static int ocfs2_fill_super(struct super_block *sb, void
*data, int silent)
osb->osb_debug_root = debugfs_create_dir(osb->uuid_str,
ocfs2_debugfs_root);
- if (!osb->osb_debug_root) {
+ if (IS_ERR_OR_NULL(osb->osb_debug_root)) {
status = -EINVAL;
mlog(ML_ERROR, "Unable to create per-mount debugfs root.\n");
goto read_super_error;
@@ -1122,7 +1122,7 @@ static int ocfs2_fill_super(struct super_block *sb, void
*data, int silent)
osb->osb_debug_root,
osb,
&ocfs2_osb_debug_fops);
- if (!osb->osb_ctxt) {
+ if (IS_ERR_OR_NULL(osb->osb_ctxt)) {
status = -EINVAL;
mlog_errno(status);
goto read_super_error;
@@ -1606,8 +1606,9 @@ static int __init ocfs2_init(void)
}
ocfs2_debugfs_root = debugfs_create_dir("ocfs2", NULL);
- if (!ocfs2_debugfs_root) {
- status = -ENOMEM;
+ if (IS_ERR_OR_NULL(ocfs2_debugfs_root)) {
+ status = ocfs2_debugfs_root ?
+ PTR_ERR(ocfs2_debugfs_root) : -ENOMEM;
mlog(ML_ERROR, "Unable to create ocfs2 debugfs root.\n");
goto out4;
}
--
2.1.0